//Accepted
#include <cstdio>

int main(){
	// freopen("in.txt","r",stdin);
	// int n, a[77];
	// a[1]=1;
	// a[2]=2;
	// a[3]=2;
	// while(scanf("%d", &n)==1){
		
		// for(int i=4;i<=n;++i){
			// a[i]=a[i-2]+a[i-3];
		// }
		// printf("%d\n", a[n]);
	// }
	int n, a[77]={ 0, 1, 2, 2, 3, 4, 5, 7, 9, 12, 16, 21, 28, 37, 49, 65, 86, 114, 151, 200, 265, 351, 465, 616, 816, 1081, 1432, 1897, 2513, 3329, 4410, 5842, 7739, 10252, 13581, 17991, 23833, 31572, 41824, 55405, 73396, 97229, 128801, 170625, 226030, 299426, 396655, 525456, 696081, 922111, 1221537, 1618192, 2143648, 2839729, 3761840, 4983377, 6601569, 8745217, 11584946, 15346786, 20330163, 26931732, 35676949, 47261895, 62608681, 82938844, 109870576, 145547525, 192809420, 255418101, 338356945, 448227521,593775046, 786584466, 1042002567, 1380359512, 1828587033};
	while(scanf("%d", &n)==1)printf("%d\n", a[n]);
	return 0;
}
